Surfactants reduce the surface tension of water by adsorbing at the liquid-gas interface. They also reduce the interfacial tension between oil and water by adsorbing at the liquid-liquid interface. Many surfactants can also assemble in the bulk solution into aggregates. Examples of such aggregates are vesicles and micelles. The concentration at which surfactants begin to form micelles is known as the critical micelle concentration or CMC. When micelles form in water, their tails form a core that can encapsulate an oil droplet, and their (ionic/polar) heads form an outer shell that maintains favorable contact with water. When surfactants assemble in oil, the aggregate is referred to as a reverse micelle. In a reverse micelle, the heads are in the core and the tails maintain favorable contact with oil. Surfactants are also often classified into four primary groups; anionic, cationic, non-ionic, and zwitterionic (dual charge).
Thermodynamics of the surfactant systems are of great importance, theoretically and practically. This is because surfactant systems represent systems between ordered and disordered states of matter. Surfactant solutions may contain an ordered phase (micelles) and a disordered phase (free surfactant molecules and/or ions in the solution).
Surfactants play an important role in many practical applications and products, including: detergents; fabric softener; emulsifiers and emulsions; paints; adhesives; inks; anti-fogging compositions; soil remediation; dispersants; wetting agents; ski wax, snowboard wax; deinking of recycled paper, both in flotation, washing and enzymatic processes; foaming agents; defoamers; laxatives; agrochemical formulations; herbicides; some insecticides; quantum dot coating; biocides (sanitizers); shampoo; hair conditioners; spermicide; firefighting; liquid drag reducing agents in pipelines; alkali surfactant polymers used to mobilize oil in oil wells; ferrofluids; leak detectors, etc.
Some surfactants are known to be toxic to animals, ecosystems and humans, and can increase the diffusion of other environmental contaminants.
Accordingly, new safe, non-toxic surfactants and methods for their use are needed. The present invention addresses these needs.